The present invention relates to a method of manufacturing a liquid crystal display device having a small cell gap, the method being suitable for the fabrication of liquid crystal display devices employing smectic liquid crystal.
Twisted nematic liquid crystal display devices (hereinafter referred to as a TN liquid crystal display device) heretofore used in watches and desktop calculators, for example, are manufactured by coating, by screen printing, a thermosetting adhesive such as an epoxy-based adhesive around a substrate comprising a sheet of glass or a plastic film with a transparent electrode formed thereon, thereafter bonding a pair of such substrates confronting each other with a gap of about 10 .mu.m left therebetween, and hardening the adhesive with heat.
Various methods have generally been employed to keep the pair of substrates spaced by the fixed gap. One method is to mix powder such as of aluminum oxide having uniform grain diameters or polymer beads of uniform grain diameters into the sealing adhesive for the substrates. According to another method, the above grainy material is dispersed in the cell so as to be uniform in density. Alternatively, short glass fibers of uniform diameter may be employed instead of the above spherical spacer.
However, in a liquid crystal display device employing a chiral smectic C phase, for example, it is necessary to select the gap between the pair of substrates to be smaller than a few .mu.m, and for this reason it is necessary to use spacers having diameters which are fractions of the diameters of the spacers which are employed in ordinary TN liquid crystal display devices. Such spacers of small diameters below a few .mu.m are expensive and must be handled with care.
One method of reducing the gap between the substrates would be to cut off a thin film of a polymer such as polyester and place it as a spacer between the substrates. However, this method is not practical as it would be difficult to cut and handle the film.